A pig model for blunt chest trauma: no pulmonary edema in the early phase
David Couret1, Sophie de Bourmont, Nicolas Prat
1Réanimation des Urgences et Médicale, Hôpital de la Timone, Université de la Méditerranée, 13005 Marseille, France. david.couret@ap-hm.fr
Objective:
Chest trauma remains a leading cause of trauma-death. Since lung contusion is one of the most important lesions implicated, the aim of this experimental study was to evaluate the cardiorespiratory consequences of an isolated lung contusion model.
Methods:
Twenty-eight anesthetized pigs were studied during four hours. We induced a right lung contusion with five bolt shots (70 joules each) using a 22-caliber charge in twenty of them. Eight others pigs constituted the control group. The trauma consequences were assessed by histology, measurements of arterial oxygenation, plasma cytokines, pressure-volume mechanics, hemodynamic monitoring using the PiCCO system and a pulmonary artery catheter. The extra-vascular lung water was measured using the gravimetric method.
Results:
Histology confirmed an isolated right lung contusion without cardiac injury. Compared to baseline values, the trauma group was characterized by a decrease in cardiac index (3.3 ± 0.8 vs 3.9 ± 1.2 l/min/m(2); P < .05) and mean arterial pressure (80 ± 21 vs 95 ± 16 mmHg; P < .05) without preload or afterload modification. Oxygenation (PaO2/FiO2: 349 ± 87 vs 440 ± 75; P < .05) and static compliance (26.3 ± 7.4 vs 30.3 ± 7.8 ml/cmH2O; P < .05) were also impaired during two hours compared to baseline. No edema was noticed in either group whatever the lung considered. All measured cytokines were below the detection threshold.
Conclusions:
An isolated right lung contusion is associated with rapid but transient cardiorespiratory impairments. Despite the large extent of the lung contusion, no pulmonary edema appeared during the period studied.
